For example, a conventional electric motor equipped with one or more magnetic sensors typically includes a stator, a magnet rotor, and magnetic sensors, all of which are received in a casing, and the sensors sense leakage flux leaking out of the magnet rotor to detect a rotational speed, angle of rotation, etc. of the magnet rotor, as disclosed in Japanese Patent Application Laid-open Publication No. 09-37512 and Japanese Patent No. 2699655, FIG. 1.
A typical example of the magnetic sensor includes a Hall element and Hall IC.
However, in the rotary electric machine equipped with one or more sensors of the foregoing structure, since a magnetic sensor and a support structure for supporting the magnetic sensor such as a circuit substrate are both received within the casing, the dimension of the casing in an extending direction of the rotation center line of the magnet rotor (that is, an axial direction) inevitably becomes long. As a result, it is impossible to make the machine thinner.
Moreover, since the casing has to be opened when the maintenance inspection of the circuit substrate is needed, it is not easy to perform the maintenance inspection of the circuit substrate in a short time.